Sportscaster Warner Wolf signed a new two-year contract yesterday with ABC television and WABC-TV, the network's New York affiliate, putting an end to reports that he would be returning to Washington this spring.

Wolf, whose boyishly enthusiastic style and features such as the "Boo of the Week" made him a Washington institution during 11 years on WTOP radio and television here, will continue to do the sports segment of WABC's 11 o'clock news five nights a week and will have some network assignments.

Wolf said he was not at liberty to discuss terms of his new contract, but called it "a very nice offer." He said his duties would be primarily with WABC.

"I'll be the first to admit that the network assignments didn't work out as well as I thought they would, but it's been an interesting 2 1/2-year association. I certainly don't regret it," Wolf said.

Wolf, 40, signed a contract with ABC in March 1975, and handled network assignments on weekends while continuing to do his weeknight shows on WTOP-TV-9, the Washington CBS affiliate, until March 1, 1976, when he joined WABC.

It had been reported that Wolf would bring his flamboyant delivery - often launched with an ebullient "Hey, man" - back to WTOP after his ABC and WABC contracts expired at the end of this month.

But for two years at least, the "Boo of the Week" is staying in the Big Apple.